Based on the provided sources, the detection of “weak signals” or outliers is overwhelmingly an emergent artifact of the “net”—defined as the specific boundary judgments, task constraints, and models chosen by the observer—rather than a property of raw individual sensory capability.

The sources suggest that “data” and “signals” do not exist as objective entities waiting to be picked up by sensitive sensors; rather, they are created or “lured” by the hypotheses and constraints (the net) imposed by the observer.

1. The “Net” Determines the Signal (Hypothesis-Dependence)

The most direct address of your query comes from Felin et al., who explicitly argue that “fishing expeditions require a net”[1].

No Hypothesis-Free Detection: Signals (or “fish”) do not “jump out and declare their relevance”[2]. Even exploratory investigation requires a “proto-hypothesis”—a latent expectation or question that directs attention[3][4].

The Net Defines the Catch: The tools, cognitive models, and statistical methods used constitute a “net.” The choice of the net (its mesh size, weight, and where it is cast) implies a hypothesis about what matters. If the net is not designed to catch a specific type of outlier, that outlier effectively does not exist for the observer, regardless of its physical presence[5].

Theory-Laden Observation: Einstein is quoted to reinforce this: “It is the theory which decides what can be observed”[6]. Data is manifest due to the hypothesis, not the other way around[7].

2. Sensory Capability vs. Task Constraints (The “Gorilla” Effect)

The limitation of “individual sensory capability” is illustrated by the “invisible gorilla” experiments discussed by Felin et al.

Capability is Insufficient: In experiments where observers were asked to count basketball passes, they missed a person in a gorilla suit walking through the scene. This was not a failure of sensory capability (the gorilla was large and visible) but a result of task constraints[8][9].

Salience is Constructed: Reductionist science assumes salience is a property of the stimulus (size, contrast). However, detection depends on the “question posed by the experimenter.” When the task changes (e.g., “look for something unusual”), the “weak signal” (the gorilla) becomes immediately detectable[10][11].

Attention as a Filter: The observer’s frame functions as a “sieve or filter”[5]. High sensory precision (e.g., expert radiologists) does not prevent blindness to massive outliers (like a gorilla inserted into a lung scan) if the observer’s internal model is tuned strictly to look for cancer nodules[9][10].

3. Outliers as Artifacts of Abstraction (The Rosen Model)

Robert Rosen’s work provides the systems-theory explanation for why the “net” necessarily excludes weak signals and why they subsequently appear as “error” or outliers.

Models are Closed Systems: A model (the observer’s “net”) is a closed system. It is an abstraction that retains only a few specific degrees of freedom (observables) and neglects all others[12][13].

Reality is Open: The natural system being observed is open to infinite interactions. A “weak signal” or outlier is often the manifestation of a degree of freedom that was abstracted away (ignored) by the model but is now interacting with the system[13][14].

Bifurcation as Detection: When the behavior of the real system diverges from the model (the “net”), a bifurcation occurs. To the observer, this appears as an “error” or a “side effect”[15][16]. This deviation is not a property of the sensor, but a measure of the discrepancy between the observer’s closed model and the open reality[14][17].

Complexity as Non-Equivalent Encodings: A “complex” system is defined by the fact that it cannot be fully captured by a single “net” (encoding). Detecting the full reality of a system requires multiple, non-equivalent encodings (nets) because a single simple model will eventually fail to predict the behavior driven by the “weak signals” it ignored[18][19].

4. Measurement as “Selective Loss of Detail” (Pattee)

Howard Pattee reinforces the view that detection is an act of exclusion, not just inclusion.

Measurement is Classification: Measurement is not a passive mirroring of reality; it is a classification of details. It maps complex input patterns to simple symbols[20][21].

The Net creates the Observation: The “net” corresponds to the constraint or the measuring device. This device must selectively ignore most details to function. If a measuring device (the net) tried to account for every detail, it would cease to function as a measure and become just another complex physical interaction[22][23].

Epistemic Cut: The observer must make an “epistemic cut” between the measuring device and the system. This cut is a choice—a “boundary judgment”—that determines what is recorded as a signal and what remains background noise[24][25].

Conclusion

The detection of weak signals or outliers is fundamentally an emergent artifact of the ‘net’.The observer’s choice of boundary judgments (where to place the epistemic cut), task constraints (what to measure), and station points (the specific encoding or model used) defines what constitutes a signal. “Weak signals” are often those degrees of freedom that were initially abstracted away by the chosen model (the net) but have begun to interact causally with the system, appearing as “error” or “bifurcation” because they violate the model’s closed logic[17][26]. Individual sensory capability is secondary; without the correct “net” (hypothesis/model), even the strongest signal (a gorilla) remains invisible[10].